Rotary screen for paper-stock



C. 8. BIRD.

ROTARY SCREEN FOR PAPER sTocK. APPLICATION FILED SEPT. 1G. i918.

Patented May 2), 1919.

2 SHEETS-SHEET l.

61115.02 wmlr C. S. BIRD.

ROTARY SCREEN FOR PAPER STCK.

APPLICATION FILED SEPT- I6. i918.

'Patented May 2o, 1919.

2 SHEETS-SHEET 2.

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UNITED ysTATns PATENT OFFICE.

CHARLES S. BIRD, OF EAST WALPOLE, MASSACHUSETTS, ASSIG-NOR TO BIRDMACHINE COMPANY, A CORPORATION OF MASSACHUSETTS.

V ROTARY SCREEN Fon PAPER-STOCK. i

Specification of Letters iatent..

Patented May'zo, 1919.

Application filed September 16, 1918. Se'ra1No.254,308.

To all 'whom it may concern:

Be it known that I, CHARLES S. BIRD, a

citizen of the United States, residing at East Talpole, in the county ofXorfolk and State of Massachusetts, have'invented certain new and usefulImprovements in Rotary'Screens for Paper-Stock, of which the followingis aspeciication.

This inventlon pertains rotary screen for paper stock.

v The invention has for its main object, the

production of a screen that will insure a constant output of stock, andwhich by reason of its peculiarb construction will require but a minimumof power to operate` it, and at the same time is durable andconsequently of long life.

A still further object is to provide means working in conjunction withthe usual water cleaning jet orf spray to remove strings and snags fromthe screen surface.

Fig. 2 a transverse vertical sectional view,

and

Fig. 3 a longitudinal vertical 4sectional view.

In the drawings, 1 denotes a suitable' frame or standard at the head endand 2. a standard or frapie at the opposite end. The screening cylinderproper may be of any approved form and in that illustratedcomprises -aclosed head 3, an open ring. shaped head 4 between which extend suitabletie rods 5, and screen supporting and attaching bars 6; rPhe screeningsurface 1s preferably formed of segmental perforated plates 7 producedfrom phosphor-bronze or `the like, which are attached by screws to theheads and bars.,

Head 3 has xedly secured thereto Ia stub shaft 8 which extendsoutwardlyvv through a stuing box 9 mounted inlstandard 1.

Said shaft has secured to it a gear 10 and.

derives its motion at a reduced speed,

through the gearing as shown, from a band wheel 11. Head 4, which is ofringform,

extends through and is supported at its to an improved outer end bysuitable bearing blocks 12 preferablyY produced from lignum-vitae heldin place in the standard 2 by a ring or collar 13. A discharge mouth 14is secured to standard 2, and the screened pulp passes therefrom into adischarge box (not shown) which is connected to the head box ofthe papermachine. f

The vat of themachine is designated by 15 and is sustained inyoke-shaped frames 16 and 17 -which latter at one side are supported bylaminated spring members 18.

the opposite side being pivotally supported from links 19, the pivotsfor the upper ends of which are sustained by standards 20. A

radius bar 21 is connected to one of the lower link pins and a pitman 22isadjustably secured thereto, the opposite end of the pitman coactingwith an eccentric 23 carried by 'a driven shaft 24. .Through thisarrangement the tank or vat is vibrated, the ahflplitudev of vibrationbeing regulated and determined by adjustment of the pitman withreference to the radius .bar orv arm 21.

A flexible connection. is effected between `each end of the vat and theadjacent standards 1 and 2 which, inA effect, form heads orends for thevat. -strips or bands of rubber, denoted by 25, Fig. 3, form aneffective simple and durable connection and are preferably held in placeby metallic straps 26 overlying the bands and .secured in place byscrews passing .into the vat body and into iianges 27 formed on therespective standards.

The vat at its lower side is provided with av drain 28 into which settlethe impurities that are held back by the screen, down- "comin-gunscreened stock assisting gravity' in this action. The impurities thuscaught :are removed in a small constant stream to a l small auxiliaryscreen (not shown), where any good stuffis removed and returned to theHow-box 29which discharges -into the vat, Fig. 2.

Projecting through the head 4 and eX- f tending .throughout the' lengthof the screen in the upper portion thereof` is a trough orV tray 30, andlocated above said tray' and within the screen is a spray pipe I havefound that 31. The water forced from said pipe passes through the screenand acts to dislodge .any matter which is heldin the screen openings orperforations, the jet carrying such maposed portion of the screensurface is again submerged. Supported in suitable bearings on'thestandards land 2 is a shaft 35 to which is imparted a rapid rotation.Said shaft carries a wiper or beater, the flexible elements 36 whereofcontact the screen sur-y face and act to yremove any strings, snags orother adhering substances therefrom. Said elements will preferably beformed of feltthough bristles or wires may be employed. Felt, however,is found preferable,"as it does not weary away readily and moreover doesnot wear away the screen.

Preferably the'screen is rotated slowly in a direction the reverse ofthat of the wiper, which latter, asabove noted, has a relatively highspeed. Any material which may pass the screen cleansing jet or spraywill therefore be removed by the wiper, such removal being facilitatedby the difference in 4speed of rotation between the screen and wiper. Ahood or guard 37 overlies the wiper,- and prevents splashing' of thewater and waste material which is removed thereby.

What is claimed isz Y l. In a machine of the character specified, thecombination of a vat, means for vibrating the same; ya screen mountedfor rotation withinsaid vat 1:' means 'for feeding the stuff tobe'screened to the vat; and a rotatable beater contacting the outer`surface of the -screen land acting upon the exposed surface thereof. p

2. In amachine of the character specified, the combination of a vat; ascreen mounted for rotation within said vat; means for feeding stuEv tothe-vat and exteriorly of the screen,-said screen havingl an inwardflow; ajet pipe located within the screen above the stuff level of lthevat; a wiper contacting the exposed outer'face of the screen aftery itpasses the jet; v wiper at a relatively high speed.

3. the combination of a vat; a screen mounted for rotation within saidvat; means for feeding stuif to the vat and exteriorly of the and means'for rotatingv the screen, said screen havin an inward flow; a

jet pipe locatedwithin elscreen above the In a machine of the characterspecified,-

after it passes the jet; and means for rotating the wiper at arelatively high speed.

4. In a machine of the character specified, the combination of a pair offrames or standards; a vat; a flexible connection between the ends ofsaid vat and frames, said frames forming the heads or ends of the vat;an inflow screen mounted for rotation inthe vat; means for vibrating thevat; a spray pipe located interiorly of the screen; and a flexible wiperacting upon the outer surface of the screen beyond the spray pipe.

5. In a machine of the character-specified, the combination of aU-shaped vat body;v a pair of frames or standards; a ange extending fromeach frame toward the body; a' rubber strip secured to 'each flange andto the adjacent end of the body and forming a closure between saidparts; means vfor vibrating said body; an iniow screen mounted forrotation within said vatg a spray pipe located interiorly of the screen;and a fiexipoint beyond the spray .the adjacent end of the body and'forming a closure between saidY parts; means for vibrating said body; ascreen mounted for rotation with said vat; and a rotary wiper embodyinga 'series of flexible members adapted to contact the exposed surface ofthe screen.

7 In a machine of the character specified, the combination of a U-shapedvat body; a pair of frames located adjacent the ends thereof; a flexibleconnecting closure between the vat ends and the frames a drain ,locatedat the lower side of the vat; means for vibrating the vat transverselyto its axis; a screen mounted in said vat, one end ,of the screen beingopen and discharging loutwardly therefrom; ta spray pipe located withinthe upper pa/rt of the screen; and a rotary-iexible beater workinglagainst the ysurface of the screen in rearof the spray pipe, saidbeater rotating in a direction the reverse of that of the screen andhaving a peripheral speed in excess of that of the screen: t l

In testimony whereof I have signed my name to this specification.

i ctns s.` Bran

